Patients with critical illnesses are more likely to survive when cared for by Intensive care unit (ICU) specialists, but a shortage of critical care-trained professionals jeopardizes the goal of providing ICU specialty care to these patients. Nurse practitioners, physician assistants and other hospital-based physicians are increasingly called upon to provide care for patients in the ICU, but many of these health professionals do not have the education or experience to safely manage these patients. This project will test the hypothesis that simulation can be used to assess whether health care professionals have the requisite knowledge and skill to provide care for patients in the ICU. Our research team includes critical care physician and nursing educators, who direct educational programs for physicians and advanced practice nurses and simulation experts who have experience in designing and implementing simulation-based assessment strategies. This multidisciplinary investigative team will construct and validate scenarios simulating conditions that require prompt diagnosis and management in the ICU. Expert physicians and nurses will be used to judge performances and their decisions about competence will be used to establish minimum performance standards to care for critically ill patients. This research strategy will provide a common assessment tool that can be used to define competence of health care professionals from the diverse professional and specialty training backgrounds that currently manage ICU patients. The methodology using expert consensus of simulation scenario performance to define a performance standard could be broadly adapted to other domains of practice. Our long-term goal is to develop methodology that uses simulation to define practice standards that could be applied to elevate practice standards and make patient care safer.